Writing instrument



Feb. 10,1953

H. c. ERENTZEL WRITINd INSTRUMENT '2 1 SHEETS-SI-iEET 1 Filed Jan. 31.1947 INVENTOR. l ermcm/ Cflenjjel,

5785- 1953 H. c, FRENTZEL WRITING INSTRUMENT 2 Sl-iEETS-Si-IEET 2 FiledJan. 31. 1947 INVENTOR. fifzrman afien'el,

Patented Feb. 10, 1953 UNITED STATES PATENT OFFIQE WRITING INSTRUMENTApplication January 31, 1947, Serial No. 725,609

My invention relates generally to ball-point writing instruments .and ithas to do particularly with a ball-point writing instrument of the typeincluding a casing in which is mounted a writing unit adapted to beprojected and retracted through an opening in the casing. 7

One of the objects of my invention is to provide an improved ball-pointwriting instrument of the foregoing character.

Another object is to provide new and improved casing structure for aball-point writing instrument which casing structure is arranged forspecial manipulation to control the projecting and retracting of thewriting unit.

A further object of my invention is to provide an improved casing forball-point writing instruments and which is provided with telescopicsections adapted upon extension to project the writing point from thecasing where it is exposed for writing and upon contraction to retractthe writing point into a concealed position within the casing.

A further object of my invention is to provide a ball-point writinginstrument having a casing formed of axially aligned telescopic sectionsenabling the casing to be lengthened for writing use and shortened forstorage purposes, the casingsections being operably connected tomechanism removably supporting a ball-point writing unit and adapted totranslate. lengthing movement of the casing sections with extensionmovement of the writing unit through the casing into writing positionand shortening movement of the casingsections into retractive movementof the writing unit to a non-writing position within the casing.

Another object of the invention is to provide a casing of simpleconstruction for a ball-point writing instrument which is operablesolely upon extension and contraction of the casing respectively toproject the writing point from the casing and hold it in projectedcondition against normal writing pressure and to retract the writingpoint into the casing and hold it therein against accidentaldisplacement.

Still another object of the invention is to provide a casing of thecharacter described adapted to detachably receive a writing unit orcartridge including a ball writing point, an ink reservoir and a feedconnecting the reservoir and the writing point, and from which casingthe writing unit can be readily removed and replaced by the user withoutdisassembling or removing the mechanism for projecting and retractingthe unit.

4 Claims. (Cl. 120-42.03)

Still another object of the invention is to provide a new and improvedwriting unit or cartridge for a ball-point writing instrument which .issimple and inexpensive to manufacture, and

has a relatively large ink capacity.

A further object of the invention isto provide a casing for a ball-pointwriting instrument of the type wherein the writing point may beretracted into the casing when not in use, which casing is adapted to beextended and contracted and which, when in extended condition, is ofsufiicient length to permit it to be held comfortably in the hand forwriting purposes and which, when in contracted condition, is short andcompact and can be conveniently carried in a small space, as forexample, a ladys purse or a gentlemans vest pocket.

Further and more specific objects of the invention are to provide acasing of the character described, which is of simple construction andis inexpensive to manufacture and assemble; which is positive andcertain in its operation and which will not stick or jam when operatedto project or retract the writing point; which can be operated toproject or retract the point upon the application of a relatively smallforce; which includes a relatively small number of separate operatingelements; and which is formed from relatively light but sturdy partsproviding an instrument which is relatively light total weight but whichmay be subjected to rough usage without injury.

Other objects and advantages of the invention will appear from thefollowing description taken in connection with the appended drawingswherein:

Figure l is a side elevational view of a writing instrument constructedin accordance with my invention, the casing being shown in contracted,non-writing condition;

Fig. 2 is a view similar to Fig. l, but with the casing shown inextended or writing condition;

Fig. 3 is a longitudinal sectional view taken along line 3-3 of Fig. 1;

Fig. 4 is a longitudinal sectional view taken along line i-4 of Fig. 2;

Fig. 5 is an enlarged, tranverse sectional view taken along line 5-5 ofFig. 3;

Fig. 6 is an enlarged, tranverse sectional view taken along line 6-6 ofFig. 3;

Fig. 7 is an enlarged, transverse sectional view taken along line il ofFig. 3;

Fig. 8 is a side elevational view of the writing instrument with thecasing in extended condition and sectioned to show the interiorconstruction; and

Fig. 9 is a view similar to Fig. 8 but with the casing shown incontracted condition.

Referring now particularly to Figs. 1 and 2, the writing instrumentcomprises a tubular casing including a forward section and a rearwardsection 2, which sections are axially aligned and arranged in mutualtelescoping relation for extension and contraction in a manner whichwill be explained more fully hereinafter. When the sections areextended, the casing is lengthened so that it may readily be grasped bythe hand of the user for writing, and when the sections are contracted,the casing is shortened into a very compact form so that it may readilybe inserted into a small pocket or container, such as a purse.

The casing section I includes a barrel portion 3 (Fig. 4) of generallycylindrical, tubular form open at both ends, and a tip member or nose 4,preferably of generally tapered form terminating in a forward open end 5of reduced diameter. The tip member '4 is detachably connected to theforward end of the barrel portion 3 as by threads 6 and 1 formed,respectively, on the rear end of the tip member 4 and the forward end ofthe barrel portion 3. Preferably, the barrel portion 3 is formed with areduced forward end portion '8 for receiving the tip member 4 and theouter rel portion H! of generally cylindrical, tubular form, open atboth ends and telescoped over the forward barrel portion 3 forlongitudinal sliding movement thereon without rotational movementrelative thereto. Disposed in, and firmly carried by, the rear barrelportion I is a sleeve I formed with a slot |2 extending longitudinallysubstantially throughout its length and receiving therein a projectionor tang l3 formed in the rear end of the forward barrel portion 3. Whenthe easing sections and 2 are moved longitudinally relative to eachother, the tang I3 rides in the slot I2 and prevents relative rotationof the casing sections.

The rear end of the rear barrel portion I0 is closed by an end piece lhaving an inner rim or flange I6 which is expanded outwardly to engagethe adjacent portion of the sleeve H and to clamp the latter against therear barrel portion l0 thus securing the end piece |5, the rear sleeveI, and the rear barrel ||l together to form a unitary structure.

A cartridge type writing unit is disposed in the forward barrel sectionand is mounted therein for limited longitudinal displacement whereby itswriting tip may be projected out of the forward end of the casingsection in which position it is exposed for writing or alternativelyretracted to a concealed position within the easing wherein it is housedand protected. The writing unit 20 comprises a body or casing 2| whichpreferably is formed from a relatively thin tubular member of generallycylindrical form and defining throughout the greater portion of itslength an ink reservoir 22. The casing 2| is provided with a taperedforward end 23 which receives a tip and feed element having a body 24 ofgenerally tapered form seated snugly in the end 23 of the casing 2| andsecured therein as by a flange 28 which, preferably, is formed as a beadon the casing 2|. The tip body 24 is formed with an extension 29 whichprojects from the casing 2| and has a ball socket at its forward end inwhich a writing ball 26 is carried for universal rotation. An ink feedpassage 21 extends through the body 24 and connects the interior of theball socket 25 with the ink reservoir 22 whereby ink may be fed from thereservoir 22 to the ball 26 in a manner which will be well understood.Since the details of construction of the ball seat and the ink feedpassage leading thereto form no part of the present invention, suchconstruction is not illustrated in detail herein, it being understoodthat any suitable type of ball mounting and feed may be employed.

Means are provided for preventing escape of ink from the rear end of thereservoir 22 and at the same time excluding air from the reservoir, thuspreventing the admixture of air and ink g. in the reservoir and theresultant possibility of air bubbles finding their way into the feedconnecting the reservoir and the ball socket and interrupting the feedof ink to the ball. This is accomplished, preferably, by disposing aflexible wall in position to close the end of the reservoir 22, whichwall in the present illustrative embodiment takes the form of a flat,elongated sac 30 disposed in the reservoir 22 and adapted to becollapsed against the wall of the reservoir when the latter is filledwith ink, as indicated in Figs. 3 to 7 of the drawings.

The sac 3B is formed of a suitable material which is impervious toliquid and air and is sufficiently flexible to remain in contact withthe surface of the ink and to follow the body of ink as ink is Withdrawnfrom the reservoir in writing. Preferably the sac 30 is formed ofmaterial which is resilient and in its normal condition is expanded tosubstantially fill the space within the reservoir 22. When ink is forcedinto the reservoir 22 to fill the latter, the sac 30 is forced into aflat, collapsed condition as illustrated for example in Figs. 3 to 7 ofthe drawings. The sac 30 has sufficient resiliency that it tends toreturn to its normal, expanded condition and thus exerts a continuous,slight pressure on the surrounding ink and. maintains a continuouscolumn of ink from the reservoir to the writing point until thereservoir is substantially emptied. The slight pressure on the ink aidsin feeding the ink and prevents the establishment of a subatmosphericpressure behind the ink which would retard or prevent the withdrawal ofink from the reservoir when the instrument is used in writing.

If desired, instead of a resilient sac, a nonresilient or limp sac maybe employed in a form generally similar to the sac shown. Such a sacserves to retain the ink in the reservoir and prevents the entry of air.This type of sac does not apply any pressure to the ink but since thesac is limp it follows the body of ink under the influence ofatmospheric pressure as ink is withdrawn from the reservoir and thus theink is maintained at atmospheric pressure.

The sac is secured suitably in position to close the rear end of thebody 2| with the open end of the sac inserted in the rear end of thebody 2! which at this portion preferably is reduced to form a neck 32having its outer end slightly flared. A tapered plug 3| secures the sac353 in the neck 32. The lip or rim of the neck 32 preferably is bentover to form a flange 33 for retaining the plug 31 in place. Theinterior of the body 2|.behind the sac 3?) is suitably vented as by apassage 34 in the plug 3| in 'order to prevent the creation 'ofsu'batmosph'ericpressure behind the sac which if it existed' mightinthe-use cf certain kinds of sacs prevent them from freely expanding "toclosely follow the body of ink as viinlr is withdrawn fromtheinstrumentin writing. The rear casing section '2 is vented toatmosphere, as by a vent H 'in the end piece IE to insure "that theinterior is maintained at atmospheric pressure. This not only providesatmospheric pressurerbehind the sac in the body 2| but also prevents theoccurrence of' any pressure changes within the .rear casin section whenthescasing sections :aireextendedor collapsed.

In order toefiectlongitudinal movement of the writing unit 2!] in the.c'asingfm projecting and retracting the writing point when-the casingis 'extended'or contracted respectively, .-a driving or actuatingmechanism is provided which carries the unit 26 and is operativelyconnected to the casing sections I and 2 for :actuation thereby. The.actuating mechanism. includes a driven sleeve 60 f (Figs. 4 and 5-)mounted-in the forwardbarrel portion 3- for'both longitudinal slidingandpartial rotational :movement with respect thereto.

The sleeve in removably and frictionally receives the writing unit 29..Rearward "displacement of the .unit in the sleeve is limited by anintu'rned lip or. rim 4| formed in "the rearward endof the sleeve 40which is engageable with the'base-of the neck 32 and by a flange 42which may comprise a bead formed in the body 2.! and adapted to abut theforwardendof the sleeve 410.

'The writing unit 29 is readily removabl from the sleeve 40 forreplacement by asimilar-unit ject or retract the writing unit 20,respectively. For this purpose the rearward sleeve 11 is formed with aprojection 01' 'tan'g' 50 which rides in a helical cam track 5'! formedin thedriven sleeve 60. Thus, when the rear casing section 2 is drawnrearwardly, the driven sleeve 40 is rotated ma counterclockwisedirection (as viewed from'the forward end of the instrument) The tang556 also serves as a stop to limit extensionof the casing sections andto prevent separation there advance and carries with it the writing"unit 20. thereby to project the forward-end of the latter out throughthe open 'en'd Bot the casing: Upon collapsing movement of :casingsections 1 and 2 the driven sleeve lil iscaused to-rotate in 'afclockwise direction (as viewed from the -forward end "of the writinginstrument) and is moved rearcasing sections may be determined bysuitably selecting the length of the guide track If or either of the camtracks :5! 01"5'6. However, preferably all of these track-stare of suchlengththaJt-the members which ride thereinfre'a'ch the ends "of theirrespective tracks simultaneously and thus all of these'members share"any stress resulting from a too vigorous manipulation of. theca-sing.Preferably the'members are so dimensioned that the forward end of therear casing section is brought into abutment with the ring 54"at the endof its forward travel.

The pitch or rise 'of .the cam track 56 relatively to the cam track 5!is so selected that the pin 52 is moved (relatively) longitudinally only"a relatively short distance when the tang 'iflfinoves through theentire extent of its travel. Thus,

while the casing sectionsiaremoved throu'ghout a relatively longextending or contracting movement, the writing unit is projected orretracted throughout a relativelyshort'distancel This short movement ofthe unit is adequate to retract the point from its projectedwritingposition to a concealed position :sumiently within the casing to preventthe point from contacting the hands or clothes of theuser. Thus,'the'writing unit may be as long as or slightly longer than the forwardcasing sectiomwithout substantially limiting the extent of collapsingmovement of the casing sections.

By providing a cam track 5| of relativel-ysteep pitch for rotating thedriven sleeve and a cam track of relativelylow'pi-t'ch for moving thedriven sleeve longitudinally, a substantial mechanical advantage isobtainedand accordingly, a r-elatively-small force is required to effectextension of. The driven sleeve 46 is 'caused'to move forforward end ofthe barrel portion 3. The pin '52 rides in a helical cam track 5'3formed in the driven sleeve to. This cam track may take the form of aslot r groove which 'tur ns"onspir'als in the same direction as thetrack '5] and a substantially flat p'itchbor low rateoi rise rliitivelyto the track 5 I.

Thus it will be seen that, when the casing is extended, and the drivenmember {30 is rotated in a counterclockwise direction (as viewed fromthe front of the instrument) the latter is caused to reversible.

or contraction of the 'casingsections'." Also, since the cam track 56has arelatively'low pitch, the connection betweenthe forward casingsection I and the driven sleeve 40is'substantiallyhon Accordingly; whenthe instrument is used in writing, the unit will not be drivnbacl'r'into the casing even though substantial writing pressure is applied' onthe point. Accidental eir tension or contraction of the casing sectionss'uh "as might oceur'in handling the instrument, as'for example wheninserting it into or removing "it from the pocket of the user, ispreventedby'providingsufficient friction between the relatively movableparts to hold theca'sing 'sections in either position of adjustment.

It will be seen from the foregoing that the present invention providesan extensible and contractible casing which is positive in its operationto control the projecting and retracting movements of a ball-pointwriting instrument. The

casing section may be contracted or extended by simple push-pullmovement and without the necessity for operating any release buttons,

latches or other mechanism or turning or twisti'ng the casing sections'The construction insures that the casing sections will remain in eitherposition of adjustment against axial displacement as, for example, whenthe instrument is inserted in or removed from the pocket or purse of theuser. The writing unit or cartridge may be readily removed or replacedby the user With out removing or disassembling the actuating mechanism.The casing may be made of such length that when extended it fitscomfortably in the hand for writing purposes and when contracted isshort and compact and can be conveniently carried in a small space as,for example, a lady's purse or a gentlemans vest pocket.

The writing unit is snugly fitted in the driven sleeve and issubstantially housed thereby. The driven sleeve thus serves to protectand reinforce the body portion of the unit and the latter is subjectedto no stress during use or operation except the pressure applied to thetip when the instrument is used in writing. Accordingly, the body may beformed of relatively thin material providing a reservoir of maximum inkcapacity for any particular diameter of unit. The construction of theactuating mechanism is such that it consumes a relatively small amountof space and thus the unit may be of a size closely approaching the sizeof the casing. Thus, a relatively large capacity ink reservoir may beprovided in an instrument of a size comparable to a conventionalfountain pen.

The instrument may be made of relatively light construtcion and yet besufficiently sturdy to provide for a long life. The parts are relativelysimple and can be manufactured inexpensively. Several of the parts as,for example, the barrel members and the cartridge body may be formedadvantageously from seamless tubing, and others as, for example, thesleeves may be formed from flat sheet material. The several members,except the sac, preferably are formed from metal such as stainless steelwhich is resistant to rust and corrosion and is sufliciently rigid forthe purposes required. Since the writing unit may be made inexpensively,it may be discarded entirely when empty and a new unit substitutedtherefor.

The casing may be formed in any one of a number of various sizes andshapes and may be ornamented, as desired. Due to the fact that a portionof the forward casing section is exposed when the casing is extended andis concealed when the casing is contracted an attractive appearance maybe created by ornamenting that portion as, for example, bylongitudinally extending lines or flutes 60 (as indicated in Fig. 2) andby having the remainder of the casing unornamented.

I believe that the operation and advantages of my invention will be wellappreciated from the foregoing description, and it is to be understoodthat, while I have shown and described one form of my invention, otherdetails and arrangements of parts may be resorted to without departingfrom the spirit and scope of my invention as defined by the claims thatfollow.

I claim:

1. A ball-point writing instrument comprising a forward tubular casingsection including a barrel portion having an open end and a tapered tipmember detachably secured to and substantially closing the open end ofsaid barrel portion and having an open forward end of substantiallysmallerdiameter than the open end of said barrel portion, a rearwardcasing section including telescoped inner and outertubular memberssecured together at their rear ends only, said forward casing sectionbeing telesconed and slidable between said inner and outer tubularmembers, means guiding said casing sections for relative longitudinalmovement only, a driven element mounted for rotation and longitudinalmovement in said forward casing section and having two helical camtracks spiraling in the same direction, studs on said forward casingsection and inner tubular member engaging said cam tracks respectively,a ball-point writing unit detachably carried by said driven element andinsertable and removable through the open forward end of said barrelportion when said tip member is removed, said unit having a ball writingpoint positioned to be projected and retracted through, the open end ofsaid tip member upon longitudinal movement of said driven element.

2. A ball-point writing instrument comprising a forward casing sectionincluding a barrel portion having open forward and rearward ends and aninwardly extending projection adjacent its rearward end, a rearwardcasing section including a barrel portion slidable over said forwardbarrel portion and concealing said projection, a driving sleeve in saidrear barrel portion and slidable in said forward casing section, andmeans connecting aid rear barrel portion and said driving sleeve attheir rear ends, said driving sleeve having a rectilinear guide trackextending longitudinally thereof and slidably receiving therein theprojection on said forward casing section for guiding said barrelsections for longitudinal movement only, a driven sleeve having twohelical cam tracks therein spiraling in the same direction, said drivensleeve being mounted for rotation and longitudinal movement in saidforward casing section, a writing unit carried in said driven sleeve andhaving a ball writing point positioned to be projected and retractedthrough the open end of said forward casing section upon longitudinalmovement of said driven sleeve, and projections carried by said forwardcasing section and said driving sleeve engaging said cam tracks,respectively, for actuating said driven sleeve to project said writingunit upon extension of said casing sections and to retract said unitupon contraction of said casing sections.

3. A ball-point writing instrument comprising a rear casing sectionincluding telescoped inner and outer tubular members secured together attheir rear ends only, a forward tubular casing section telescoped andslidable between said inner and outer tubular members, guide meansguiding said forward and rearward casing sections for longitudinalrelative sliding movement only, a driven sleeve telescoped in saidforward section and said inner tubular member and completely concealedby the forward section and formed with helical cam tracks thereinspiraling in the same direction, one of said cam tracks having arelatively fiat pitch and being located forwardly of the forwardmostposition of said inner tubular member and the other cam track having arelatively steep pitch and being located rearwardly of said first-namedcam track, studs on said forward casing section and inner tubular memberengaging said cam tracks respectively, and a ball-point writing unitinsertable through the forward end of and removably carried by saiddriven sleeve with its point positionedto be projected through theforward end of said forward casing section upon relative slidingmovement of said casing sections.

4. A ball-point writing instrument comprising a forward casing sectionincluding a barrel portion open at both ends and havine an imnerforate 2peripheral surface and a tapered tip member detachably secured to andsubstantially closing the open forward end of the barrel portion, thetip member having an open forward end, a driven element mounted forrotation and longitudinal movement in said forward casing section, aballpoint writing unit detachably carried by said driven element andinsertable and removable through the open forward end of said barrelportion when said tip member is removed, said unit having a ball writingpoint positioned to be proiected and retracted through the open end ofsaid tip member upon longitudinal movement of said driven element, saiddriven element having a first, forward helical slot of fiat pitchadjacent its forward end and a second, rearward helical slot of steeppitch extending substantially the full length thereof, a stud fitted inan opening in said barrel portion and extending into said first slot,means on said barrel portion for securing said stud in the opening andconcealing the same and removable therefrom upon removal of said tipmember, a rear casing section including outer and inner tubular memberstelescoped with and slidable relatively to said forward casing section,said outer tubular member being imperforate and telescoped over saidbarrel portion and the inner tubular member being telescoped betweensaid barrel portion and driven element, said first slot 10 being locatedforwardly of the forwardmost position of said inner tubular member, saidinner tubular member having a stud extending into said second slot, andmeans constantly and en tirely concealed by said outer tubular membercoacting between said inner tubular member and barrel portion forguiding the casing sections for relative longitudinal movement only.

HERMAN C. FRENTZEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 5,384 Hicks Apr. 29, 1373 Re.5,518 Downes Aug. 5, 1873 160,924 Mabie Mar. 16, 1875 1,583,718 HudsonMay 4, 1926 2,400,679 Biro May 21, 1946 2,427,068 Randolph Sept. 9, 19472,444,003 Chesler June 22, 1948 2,444,004 Chesler June 22, 1948 FGREIGNPATENTS Number Country Date 83,807 Germany 1895 84,050 Germany 1895

